Hornady Custom .450 Bushmaster 250gr FTX 20rds 82244 - $25.49 BIG BORE PERFORMANCE FOR THE AR PLATFORM.
Nicknamed "The Thumper," the 450 Bushmaster is the most radical cartridge ever chambered in production AR-15 type firearms. Hornady brings big bore performance to the most popular semi-automatic rifle in America — opening a whole new world of hunting to the battle-proven platform.
Hornady engineers worked closely with the Bushmaster design team building the cartridge to wring every last ounce of performance from the AR-15 without sacrificing any strength or reliability./

PSA 300 AAC 12" SQR 11" Pistol Upper NO BCG or Charging Handle - $399.99 shipped Barrel: A proprietary blend of Hammer forged chrome molly vanadium made by FN that is referred to as "Machine Gun Steel" by virtue of its use in FN's M249 and M240 weapons. The hammer forging process work hardens the steel, making it more durable. In addition, the chrome process for the bore allows for a lining almost twice as thick as a standard M16 for enhanced durability. Chambered in 300AAC Blackout, with a 1/8 twist, M4 barrel extension, and a Pistol length gas system. A2 style profile is Mil-spec phosphate coated, MP and HP tested.

PSA 16'' 6.8 SPC II 1:11 Mid-length Modified A2 Profile - Without BCG & Charging Handle - $299.99 + $17 S/H Barrel: A proprietary blend of Hammer forged chrome molly vanadium made by FN that is referred to as "Machine Gun Steel" by virtue of its required use in FN's M249 and M240 weapons. The hammer forging process work hardens the steel, making it more durable. In addition, the chrome process for the bore allows for a lining almost twice as thick as a standard M16 for enhanced durability. Chambered in 6.8 SPCII, with a 1/11" twist, M4 barrel extension, and a Mid-length gas system. The modified A2 profile barrel is Mil-spec phosphate coated, High Pressure tested and Magnetic Particle inspected.